Designation:F2771−10StandardTestMethodforDeterminingtheLuminanceCurveofanElectroluminescentLampatAmbientConditions1ThisstandardisissuedunderthefixeddesignationF2771;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodestablishestheproceduresfordeter-miningthevisibleperformancechange,whichisdefinedbyluminance,colorandcosmeticappearanceofanelectrolumi-nescentlampduringoperationoveranextendedtime.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2F1595PracticeforViewingConditionsforVisualInspectionofMembraneSwitchesF2359TestMethodforDeterminingColorofaMembraneSwitchBacklitwithDiffuseLightSourceF2360TestMethodforDeterminingLuminanceofaMem-braneSwitchBacklitwithDiffuseLightSource3.Terminology3.1Definitions:3.1.1luminance,n—measureofthebrightnessorluminousintensityoflight,usuallyexpressedinunitsofcandelaspersquaremetre(cd/m2)orfootlamberts.1fL=3.426cd/m2.3.1.2luminancecurve,n—agraphicalrepresentationofthevariationofluminancewithtime(implicitlyunderunvaryingoperatingconditions).3.1.3electroluminescentlamp(ELlamp),n—essentiallyacapacitorstructurewithphosphorandadielectricsandwichedbetweenelectrodes,oneofwhichistransparenttoallowlighttoescape.Applicationofanacvoltageacrosstheelectrodesgeneratesachargingfieldwithinthephosphor,whichcausesittoemitlight.3.1.4timetohalfluminance(THL),n—theelapsedoperat-ingtimeoverwhichtheluminanceofalampmaintainedunderconstantpowerconditionsisreducedto50%ofitsinitialvalue.3.1.5membraneswitch,n—amomentaryswitchingdevice,inwhichatleastonecontactison,ormadeof,aflexiblesubstrate.4.SummaryofT...
